diff --git a/src/griffe/dataclasses.py b/src/griffe/dataclasses.py
index 6ecc568a..afc7ec5b 100644
--- a/src/griffe/dataclasses.py
+++ b/src/griffe/dataclasses.py
@@ -1300,7 +1300,12 @@ def as_dict(self, **kwargs: Any) -> dict[str, Any]:
             A dictionary.
         """
         base = super().as_dict(**kwargs)
-        base["filepath"] = str(self._filepath) if self._filepath else None
+        if isinstance(self._filepath, list):
+            base["filepath"] = [str(path) for path in self._filepath]
+        elif self._filepath:
+            base["filepath"] = str(self._filepath)
+        else:
+            base["filepath"] = None
         return base